It tends to run to flower too quickly if/when the weather gets properly hot.
If yours is only just starting to crop, and the weather doesn't get boiling in April, you should certainly get plenty of spears into May, I would have thought. It normally crops for at least couple of months or more, depending on variety and how patient you are at picking the increasingly small spears.
I've got white sprouting just about to start cropping, looking forward to that. :)
Enjoy your psb - there is nothing like the taste of your first ever crops!